Chess is one of the world's most popular games. Its popularity and complexity make it an interesting research domain for artificial intelligence. It is a perfect information game, meaning that both players know the entire state of the game at any given time, but that doesn't make it easy for either humans or machines to master. Chess playing machines have been the subject of human interest for hundreds of years, but only on the last few decades have they been able to compete with (and beat) the top human players.